Count complete pieces within each stock length before rounding the order. Total finished metres and total leftover metres do not describe a feasible allocation by themselves.
Confirm that the identical-piece model fits
Record the material and section, actual stock length, identical finished piece length and required whole-piece count. Include chosen spare pieces explicitly in that count. Exclude unsuitable stock and record defects separately; this model does not find usable paths around them. All example dimensions are fictional, not structural or product specifications.
Use this for quantity planning, not machine operation. It does not approve a blade, workholding or a cutting sequence. If pieces differ in length, need mitres, grain matching or end joints, make a separate reviewed cut list; do not call this one-length result an optimised mixed-length plan.
Keep end trim and kerf separate
Enter both unusable ends together as end trim in metres. Include any end-squaring loss there if it is not in the per-piece allowance; do not count the same loss twice. Enter actual cutting width as kerf in millimetres, not blade plate thickness. Obtain that input from the applicable tooling information or competent operator, not by approaching a running blade.
The existing calculator reserves one full kerf for every required piece, even if a real final piece could use an existing end. Thus it can be conservative. Zero kerf is only a comparison scenario, not advice to ignore cutting loss. Verify the actual cutting arrangement independently before buying.
Account for every stock, not one pooled remainder
Example: 2.40 − 0.02 = 2.38 m usable per stock. A 0.40 m piece plus 3 mm kerf uses 0.403 m; five use 2.015 m, leaving 0.365 m. Six would need 2.418 m, so they do not fit. Twenty identical pieces need four stocks, not merely 8.00 / 2.40 rounded up without loss.
The four remainders total 1.460 m, but none of those individual remainders is 1.460 m long. Label each stock and its own remainder. Purchased length balances as 9.600 = 8.000 finished + 0.060 reserved kerf + 0.080 trim + 1.460 unallocated m. Unallocated is not automatically scrap or usable inventory; keep its actual size and suitability.
Hand over a reviewed cut list, not a machine procedure
For only seven pieces under the same assumptions, a 5 + 2 allocation leaves 0.365 m and 1.574 m, total 1.939 m. That total still is not a single long piece, and alternative allocations can distribute the same total differently. Do not promise an extra 1.939 m component without an actual stock-level check.
Keep the versioned parts list, unit conversions, chosen tooling allowance, stock IDs and planned allocations together. Cutting belongs with a competent person using the exact equipment instructions and appropriate safeguards. The linked HSE source concerns UK workplace training; it is not local legal advice or a household cutting tutorial. If a safe suitable process is not available, use an appropriate cutting service.
HSE: woodworking training and competence (English; UK workplace scope, not a cutting procedure) ↗Example allocation: four separate stock lengths
| Stock ID | Finished pieces | Unallocated length |
|---|---|---|
| A | 5 × 0.400 m | 0.365 m |
| B | 5 × 0.400 m | 0.365 m |
| C | 5 × 0.400 m | 0.365 m |
| D | 5 × 0.400 m | 0.365 m |
Worked example
Twenty identical pieces, not mixed-length optimisation
Fictional 2.40 m stocks, 0.02 m combined end trim, 0.40 m finished pieces and 3 mm reserved kerf per piece. Required count is 20, including any chosen spares.
U = 2.400 − 0.020 = 2.380 m q = floor(2.380 / (0.400 + 0.003)) = 5 N = ceil(20 / 5) = 4 9.600 = 8.000 + 0.060 + 0.080 + 1.460 m
Four whole stocks provide five planned pieces each. Keep the four 0.365 m remainders separate; 1.460 m is an accounting sum, not an extra long component.
What to have ready
- Material, section and actual stock lengths recorded
- One finished length and explicit count including spares
- Both ends and per-piece kerf separated with correct units
- Stock-by-stock piece and remainder record
- Competent review of the actual safe cutting process
Common mistakes
- Ordering from finished metres alone.
- Entering 3 mm as 3 m or using blade plate thickness as kerf.
- Counting end-squaring loss twice.
- Calling total remainders one usable long piece.
- Treating a quantity result as mixed-length optimisation or permission to operate machinery.
Tools for these measurements
Prepare the measurements with these instrument guides.
Use and limitations. Sources include US public agencies. Principles are general; regulations and design values must be checked where you live.Worked examples use stated hypothetical inputs.